基于3D打印矩形板件的轴压屈曲试验研究

Experimental Study on Axial Compression Buckling of Rectangular Plates Based on 3D Printing

针对刚性基底上矩形板件的局部稳定问题,制作了4组不同宽厚比参数的光固化3D打印树脂矩形薄壁管进行基于数字图像相关(DIC)技术方法的轴压试验,可视化研究了矩形板件在单侧约束条件下的受压屈曲演化过程,同时进行了树脂材料的拉伸材料性质试验。引入基于Koiter理论的p-w^(2)预测方法,利用该方法预测试验结果的实际屈曲荷载,将试验结果与理论计算屈曲荷载结果对比分析。结果表明:与无侧向约束的自由板件相比,侧向约束作用可以提升板件屈曲荷载和极限强度,该效果最少可达到1.5倍和1.7倍;较薄板件具有更大的初始缺陷,侧向约束无法对形成紧密约束,导致其屈曲波长和自由板件相差不大;对于自由板件,其理论屈曲荷载值较拟合屈曲荷载值总是偏大,而对于受侧向约束作用的板件,理论屈曲荷载的预测效果较好,证明了理论计算方法和p-w^(2)拟合方法的可靠性。

Aiming at the local stability of rectangular plates on rigid substrates,four groups of light-cured 3D printed resin rectangular thin-walled tubes with different width-to-thickness ratio parameters were fabricated for axial compression tests based on digital image correlation(DIC)technology.The compression buckling evolution process of rectangular plates under unilateral constraints was visually analyzed,and the tensile material properties of resin materials were tested.A prediction method p-w^(2) based on Koiter theory is introduced to predict the actual buckling load of the test results.The test results are compared with the theoretical calculation results.The results show that compared with the free plate without lateral restraint,the lateral restraint can improve the buckling load and ultimate strength of the plate,and the effect can reach 1.5 times and 1.7 times at least.Compared with the thin plate,it has a larger initial defect,and the lateral constraint cannot form a tight constraint,resulting in a small difference in the buckling wavelength between the free plate and the thin plate.For the free plate,the theoretical buckling load value is always larger than the fitted buckling load value,while for the plate subjected to lateral restraint,the theoretical buckling load has a better prediction effect,which proves the reliability of the theoretical calculation method and the p-w^(2) fitting method.